import sys

def main():
    if len(sys.argv) != 3:
        print("Usage: python concat.py <param1> <param2>")
        return
    
    param1 = sys.argv[1]
    param2 = sys.argv[2]
    
    # 返回拼接后的字符串
    print(param1 + param2)

if __name__ == "__main__":
    main()
